1. Field of the Invention
The present invention relates to flow control valve assembly, and more particularly to a servo hydraulic flow control valve assembly.
2. Description of Related Art
A conventional hydraulic flow control valve in accordance with the prior art usually uses the rated relief valve to control the pressure. However, the conventional hydraulic flow control valve has some disadvantages that need to be solved.
1. It is inconvenient. The rated relief valve is operated only when the pressure of the system exceeds the rated pressure. Consequently, the conventional relief valve lacks a fine turning capability and is unsuitable for some precise machine.
2. The conventional hydraulic flow control valve low in safety. The pressure of the conventional hydraulic flow control valve is highly rated. Consequently, the high pressure may damage the system and cause a leak of the fluid when the rated pressure is too high.
An automatic grinding machine, with a changeable hydraulic pressure, has a work pressure that is changed relative to the processes of grinding work piece. However, the machine with a changeable hydraulic pressure cannot release pressure in time when the system pressure exceeds the rated pressure because the conventional control valve only controls the pressure in the inlet. Consequently, the buffer margin of the machine is reduced.
The present invention has arisen to mitigate and/or obviate the disadvantages of the conventional hydraulic flow control valve.